In recent years, as smart home appliances having an Internet access function to home appliances and application programs embedded therein are getting popular, the number of smart devices owned by a user is gradually increased. The smart devices may access the Internet through a network, and transmit and receive data to and from devices through the network. In this case, when a user possesses a plurality of smart devices, data may be synchronized with the plurality of smart devices through the network.
In terms of the data synchronization method, Korean Patent Laid-Open Publication No. 2013-0013804 discloses a device for character and voice synchronization output device. However, these smart devices need communication modules such as WiFi or Bluetooth for data synchronization and the smart devices having the communication modules embedded therein cannot but be expensive. Further, a method for data synchronization using a communication module has a complicated procedure, and as a result the user may feel uncomfortable. Therefore, a method for data synchronization which may be cheap and readily available by anyone is required.